The present invention is directed to golf balls, and more particularly to a ball having the optimal core compression, core diameter, cover hardness, and dimple configuration to provide superior distance capabilities.
It is well known in the golf industry that the distance a ball travels is one of the key features that distinguishes one ball from the next. In the golf ball business, distance sells.
Ball manufacturers are bound by regulations of the United States Golf Association (USGA) which control many characteristics of the ball, including the size and weight of the ball, the initial velocity of the ball when tested under specified conditions, the overall distance the ball travels when hit under specified test conditions, and the ball""s aerodynamic symmetry. Under USGA regulations, the diameter of the ball cannot be less than 1.680 inches, the weight of the ball cannot be greater than 1.620 ounces avoirdupois, the initial velocity of the ball cannot be greater than 250 feet per second when tested under specified conditions (with a maximum tolerance of +2%), the driver distance cannot exceed 280 yards when tested under specified conditions (with a test tolerance of +6%), and the ball must be spherically symmetric in an aerodynamic sense.
While the USGA sets a limit for the distance a ball can travel under set test conditions, there is no upper limit on how far a player can hit a ball. In the effort to design a ball with superior distance capabilities, one area that ball manufacturers have looked to is dimple configurations. For example, U.S. Pat. No. 4,886,277 discloses the projection of a truncated octahedron onto the ball as a basis for a dimple configuration. A truncated octahedron is formed by removing portions of the eight sided octahedron which results in a solid with six (6) squares and eight (8) hexagons. The preferred ball disclosed in this reference has a minimum of four (4) uninterrupted great circle paths present on the dimpled ball, and a major portion of the dimples present on the ball are within the boundaries of either a spherical hexagon or square. U.S. Pat. No. 4,765,626 discloses a golf ball having a dimple pattern based on the truncated octahedron used in conjunction three orthogonal uninterrupted parting lines which coincide with the diagonal bisectors of the squares.
A problem with the prior art dimple configurations is that they fail to take into account other features of the ball, such as core size, core compression and cover hardness, which also influence how far a ball will travel.
U.S. Pat. No. 5,368,304 to Sullivan discloses a ball having a low spin rate, which in turn enables the ball to travel greater distances. According to the Sullivan patent, the low spin rate is the result of a soft core and hard cover. While the ""304 patent discloses the use of a soft core and hard cover to lower the spin rate, it does not disclose a dimple configuration for the ball.
There is a need to develop a superior distance ball that takes into account not only the dimple configuration, but also the core compression, core diameter and cover hardness.
It is an object of the present invention to provide a golf ball which has superior distance capabilities.
It is another object of the present invention to optimize the combination of core compression, core size, dimple configuration and cover hardness to provide a golf ball which travels great distances, and at the same time complies with USGA regulations.
The golf ball of the present invention is based on the recognition that it is the combination of the dimple configuration, dimple size, dimple shape, core compression, core size, and cover hardness that produces a ball that will travel the greatest distance.
The ball of the present invention has a core compression in the range of 77 PGA to 87 PGA; a core diameter in the range of about 1.532 inches to about 1.548 inches; a cover hardness in the range of about 66 Shore D to about 72 Shore D; and a dimple pattern based on the geometry of a truncated octahedron. This combination has been found to produce a ball with superior distance capabilities which also satisfies USGA regulations.
The dimples are arranged on the surface of the golf ball based on the geometry of a truncated octahedron. A truncated octahedron is formed by, as the name implies, removing portions of an eight sided octahedron. This removal results in a solid with six (6) squares and eight (8) hexagons. This solid is projected onto the surface of the golf ball so that the two opposing poles of the golf ball coincide with the centers of two opposing hexagons. This projection defines an equatorial great circle path which is then utilized as the mold parting line for the golf ball. This mold parting line, as typical with most golf balls, will not be intersected by any dimples. Dimples may, however, intersect any or all projected sides of any polygonal structures, so long as this intersection is performed in a symmetrical fashion over the entire surface of the golf ball. It is preferred, but not required, that if any such intersection exist, the dimples are equally divided for the most part by any of the intersecting lines.
The present invention is flexible in that it is not as restricted in the placement of dimples as the prior art balls, and therefore utilizes the natural symmetry of the solid more effectively.
The core has a compression of 77 to 87 PGA, and a diameter of 1.532 inches to 1.548 inches. The cover has a hardness of about 66 Shore D to about 72 Shore D.